LG 26LH1DC1-UB Service Manual page 38

5. AV1, AV2, AV3 Video signal flow chart
AV1, AV3 Input
External input AV1 and AV3 are received through the RCA jack of P703, and AV2 is received through the 6 pin
wafer of CN105.
These signals all come to the analog video switch(IC706) and only 1 signal is selected. In other words, it is the same
as the analog RF signal.
The one signal that has been selected for output is decoded in the DTV controller and converted to LVDS signal to
be sent to the LCD panel through the LVSD connector(P503).
Also the output signal from the analog video switch is used for caption.
The signal received from IC107 is filtered and amplified 2 times to be received by the microprocessor.
The microprocessor analyzes(caption slicing) this signal to send the caption information.
Copyright©2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
AV2 Input
RCA Jack
LCD Panel
*Composite(AV1, 2, 3) Video signal flowchart
P703 CN105
Wafer
CVBS
CVBS
IC706
for Caption
Analog MUX
(Video switch)
CVBS
IC401 I 2 C Comm.
DTV Controller
LVDS Signal
P503
LVDS Connector
-38-
IC107
SD Video Filter
IC705
Micro Processor
LGE Internal Use Only